Put raisins in a small bowl and fill with enough warm water to just cover the tops of them. Set aside and let plump.
Meanwhile, in the bowl of a stand mixer, combine the yeast, warm water and sugar. Stir gently and let sit and froth for about 10 minutes.
Once the yeast is frothy, add the pumpkin, molasses, brown sugar, salt, spices and raisins (drained of their water) and mix with the paddle attachment on low speed.
Switch out the paddle attachment for the dough hook on the stand mixer.
Add 2 cups of the flour and mix on medium low speed.
Add the remaining 2 cups of flour gradually as the dough mixes.
Mix for about 5 minutes. The dough should be relatively firm and not too sticky by the end and formed into one nice ball.
Transfer the ball of dough to a greased bowl, cover with a towel and let rise in a warm spot until doubled in size (about an hour).
Once risen, punch the dough down on a countertop.
Divide the dough into 12 even pieces.
Roll each piece into a ball, flour your thumbs and poke through the center of the ball with your thumbs. Work the dough around your thumbs until the center hole is about 1½-2 inches wide. Set the bagels onto a greased baking sheet and cover with a towel. Let the bagels rest for 20-30 minutes.
Meanwhile, bring a large pot of water to a boil and preheat the oven to 450 degrees.
Add the baking soda to the pot once boiling.
Carefully drop in 2 bagels at a time, boiling for about 30 seconds per side.
Remove the bagels with a slotted spoon and place on another baking sheet that's been greased and dusted with cornmeal.
Repeat boiling process until all bagels have been boiled.
Bake the bagels (you'll probably have to do 2 baking sheets) for 10-12 minutes until they start to turn golden brown. You can brush them with butter or an egg wash before baking for a more "glossy" look if desired.
Transfer the bagels to a cooling rack once out of the oven and let cool.